Suggest Treatment For Recurring Bladder And Urinary Tract Infections

I have a recurring battle with bladder/urinary tract infections due to kidney stones. I have two bottles of ampicilina (my brother got in Mexico) that have not been opened. The expiration date is Dec 09. I was having symptoms of a bladder infection and took one pill. Was this a wise decision and could I continue to take a pill until I am satisfied that the infection is gone. My symptoms vanished after the one pill. Thank you for your assistance.